It turns out that as it collects information about you or pulls in that annoying banner ad to show you, it’s doing things like flipping on your GPS chip or activating the 3G radio in your phone — and then doing the whole crappy roommate routine, leaving them on well after they’re done using them because, eh, I don’t pay the power bill, amirite?

Shockingly, the people coding this stuff didn’t bother to make it energy efficient because screw you, you’re not paying for their app anyway. In some cases, it’s so bad that it literally takes another app to tell these components to shut off.

In short, limit your use of free apps (or just uninstall the bastards completely), and buy the apps you need. Either that or get a spare battery. (The Mophie Juice Pack is a good one.)